Scotsman MAR 305

Page 18

Page 18

SECTION II

OPERATING INSTRUCTION

1. COMPLETE UNIT START-UP

1. Remove all panels and open the water supply line shut-off valve for both the evaporator drum and in the case of a water cooled machine, to the condenser.

2. Observe the water filling operations.

a) Water flows into the float reservoir first.

b) Water is filling the freezing drum basin.

c) Float moves up as water level rises in water reservoir.

d) Float stops water flow when water level reaches maximum level in water basin, that is: 115-120 mm for MAR 55-75-105-125,

90-95 mm for MAR 205-305.

Now, water surrounds bottom half of freezing drum.

3. Move the manual ON-OFF toggle of main disconnect switch to ON position and turn counterclockwise the timer knob to start the automatic ice maker operation. The green light on console panel will glow.

4. Observe immediately that evaporator drum rotates in the right direction, namely toward the scraping blade.

WARNING - Correct Drum rotation - The evaporator drum drive motor is a threephase motor wired for 400 V. It is of extreme importance to check immediately upon unit start-up that motor rotates

CLOCKWISE in order that gear motor pulley rotates in the direction of the

ARROW. Should the motor turn counterclockwise, it is necessary to instantly switch-off the unit and interchange one polarity at terminal block connection of main electric cord.

NOTE. A double Pulley is provided for two different RPM of revolving drum. This pulley is fitted on output shaft of drive motor.

MAR air and water cooled versions are supplied from factory with the V belt placed on the smaller pulley for thicker ice scale production while drum r.p.m. are the following:

MAR 55 (0.9) - MAR 75 (1.1) - MAR 105 (1.5)

- MAR 125 (2.4) - MAR 205 (1.05) and

MAR 305 (1.6 A/C - 1.8 W/C).

5. Make sure that the automatic expansion valve opens and that refrigerant fluid starts to flow through it.

NOTE. At first compressor start-up, the suction pressure declines rapidly to 0.2 bar, causing the intervention of the pressure control, which will interrupt the entire unit operation.

This control being automatic re-set type, will resume the unit operation after few seconds.

The unit will start and stop few more times, due to the lo-pressure control cut-out and in, until system refrigerant pressure set on their normal values.

6. After two or three minutes of operation, observe that ice skin begin to form on the revolving drum surface and it is scraped by the blade.

7. Left the system operate for about 20 minutes.

Check for any excess noise beyond normal compressor noise.

a) Vibrating type from touching lines.

b) Compressor loose at one or more holddown bolts.

c) Drivemotor pulley misaligned with gear box pulley causing V belt vibration.

d) Check compressor oil level through sight glass

(Except MAR 55/75/105/125).

8. On water cooled machine check the water flowing out from condenser to see if it is correct. Cooling water flow is controlled by a pressure water regulating valve. No valve adjustment of water valve should be necessary unless the inlet temperature of cooling water is relatively high. Normal head pressure should be 17 bar on MAR 55, MAR 75, MAR 105 and

MAR 125; 16 bar on MAR 205 and 14 bar on

MAR 305.

9. Observe that evaporator drum is frosted allover from end to end. If this is not the case setting of the refrigerant expansion valve may be necessary. For proper adjustment of this valve turn the valve setting steam of one eight of a turn counterckwise to allow more refrigerant flow until the evaporator drum surface is evenly frosted from end to end.

In case you have an excessive frost back in the suction line and frost starts to form on compressor suction service valve slightly turn clockwise the expansion valve setting stem until the frost back on compressor service valve melts over.

The suction pressure should range between 0.6 bar and 2.5 bar depending on model, water temperature and level.

See indications on page 26.

Page 19

2. WATER AND REFRIGERANT CIRCUIT

Page 19

1. Compressor

2. Condenser

3. Discharge line

4. Drier

5. Liquid line

6. Heat exchanger

7. Expansion valve

8. Vapor line

9. Vibration absorbers

10. Condensing water-inlet

11. Condensing water-outlet

12. Water regulating valve

13. Drum water basin

14. Evaporator drum

15. Refrig. lines manifold.

16. Scraping blade

17. Float reservoir

18. Spray bar

19. Water pump

10. Throughly explain the owner/user the significant specifications of the MAR ice maker, the start-up and operation, going through the procedure in the operating instructions. Answer all questions about the icemaker, by the owner and inform the owner of the name and telephone number of the

Scotsman Service station serving him.

11. Fit and secure all unit panels previously removed.

WARNING - Whenever stopping the machine to keep it off operation for some time, it is recommendable to shut close the water inlet valve to interrupt the water supply.